1. Field of the Invention
The present invention relates to a liquid container and a liquid consumption. More particularly, the present invention relates to an ink cartridge to which a piezoelectric device detecting an ink consumption state inside an ink cartridge supplying the liquid to a printing head is mounted and to which a memory means that stores ink consumption data detected by the piezoelectric device is mounted.
2. Description of the Related Art
In an ink-jet recording apparatus, a carriage thereof is comprised of a pressure generating means which pressurizes a pressure generating chamber and a nozzle opening which discharges the pressurized ink therefrom as ink droplets. The ink-jet recording apparatus is structured such that ink from the ink tank is being supplied to a recording head via a passage, so as to continuously perform a printing operation. The ink tank is structured as a cartridge in a detachable manner so that a user can replace it when ink is consumed out.
Conventionally, as a method of controlling the ink consumption of the ink cartridge, a method is known of controlling the ink consumption by means of a calculation in which the counted number of ink droplets discharged by the recording head and the amount of ink sucked in a maintenance process of the printing head are integrated by software, and another method of controlling the ink consumption in which the time at which the ink is actually consumed is detected by directly mounting to the ink cartridge the electrodes for use in detecting the liquid surface, and so forth.
Moreover, in the calculation-based method of controlling the ink consumption by integrating the discharged number of ink droplets and the amount of ink or the like by the software, there is a problem where the ink consumption amount inside the ink cartridge can not be detected. As for the method of controlling by electrodes the time at which the ink is consumed, there remain problems such as limitation to the types of ink and the complicated sealing structure of the electrodes and so on though a structure for detecting the ink consumption may be somehow proposed.
However, in the calculation-based method of controlling the ink consumption by integrating the discharged number of ink droplets and the amount of ink or the like by the software, there are problems where an error occurs due to a printing mode and so on at a user's side and another unwanted error occurs when the same cartridge is mounted again. Moreover, the pressure inside the ink cartridge and the viscosity of the ink change depending on usage environment such as ambient temperature and humidity, elapsed time after an ink cartridge has been opened for use, and usage frequency at a user side. Thus, a problem is caused where a considerable error occurs between the calculated ink consumption and the actual ink consumption.
On the other hand, in the method of controlling by electrodes the time at which the ink is consumed, as disclosed for example in the Japanese Patent Application Laid-Open No. Hei8-34123, whether or not the ink is present can be controlled with high reliability since the liquid surface of ink can be actually detected. actual ink consumption can be detected at one point. However, since detecting the liquid surface of ink relies on the ink conductivity, there are problems in that types of ink which can be detected might be limited and a sealing structure of the electrodes becomes complicated. Moreover, since precious metal is usually used as the electrode material, which is highly conductive and erosive, manufacturing costs of the ink cartridge increases thereby. Moreover, since it is necessary to attach the two electrodes to two separate positions of the ink cartridge, the manufacturing process increases, thus causing a problem which increases the manufacturing costs.
Moreover, when the ink cartridge scans together with the recording head of the ink-jet recording apparatus, there are occasions where undulated waves are caused and bubbles generated. The bubbles may cause erroneous operation in the course of detecting whether or not the ink is present. In particular, in apparatus which directly detects the ink consumption amount using the electrodes to control the point at which the ink is consumed, the erroneous operation due to bubbles are significant.
There is an occasion where a cavity is provided in an ink detecting portion inside the cartridge, in apparatus which directly detects the ink consumption amount using the electrodes to control the point at which the ink is consumed. That there exists ink in the cavity may cause erroneous detection.